--- a/drivers/usb/serial/usb-serial.c	2012-10-08 07:02:14.450118292 +0300
+++ a/drivers/usb/serial/usb-serial.c	2012-10-08 07:02:24.720154214 +0300
@@ -35,9 +35,7 @@
 #include <linux/usb/serial.h>
 #include "pl2303.h"
 
-#if CONFIG_USB_SERIAL_OPTION
 #include <linux/smp_lock.h> /* brucehou, 2010/05/21, for lock_kernel & unlock_kernel */
-#endif
 
 /*
  * Version Information